Suspension for tracklaying vehicles



21,1930, y HAQKNOX. 7 A1,744,229

SUSPENSION FOR TRACK LAYING VEHICLES Filed Aug. 27, 1924 4 Sheets-Sheet 1 DDD Jan. 217 1930.

H. A. KNOX SUSPENSION FOR TRACK LAYING VEHICLES Filed Aug. 27, 1924 4 Sheets-Sheet 2 H. A. KNox y Jan. 21, 193Qff l 'v-'sl'iJsPENsIoN FOR TRACK LAYING VEHICLES anhin/a1;

4 Sheets-Sheet 4 Filed Aug. 2'?, 1924 me/nto@ A Knnx' Patented Jan. 2l, 1930 UNITED STATES HARRY A. KNOX, OF DAVENPORT, IOWA SUSPENSION FOR TRACKLAYING VEHICLES Application filed August 27, 1924. Serial No. 734,510.

(GRANTED UNDER THE ACT AF MARCH 3, 1883, AS AMENDED APRIL 30,1928; 370 0. G. 757) The invention described herein, if patented, .may be manufactured and used by or for the Government for governmental purposes without the payment to me et any royalty .3 thereon.

The subject ot this invention is a suspension for track laying vehicles.

In vehicles of the track laying type the weight of the vehicle is supported on trucks,

lo which carry wheels or rollers riding on a continuous rail formed by or on the inner side otl an endless flexible track. The irregularities and obstructions in ther path of travel entail considerable shock to the supporting 1.5 rollers and to the vehicle.`

In order that the rollers might contorni to the contour of the ground over which the vehicle passes it has been customary to pivot the trucks to the frame or to each other so that each truck might he i'ree to move in a substantially vertical plane against a yielding connection between the trucks and the main frame of the vehicle. To provide greater stability than the above structure was thought to afford it has also been proposed to omit one or more of the resilient connec tions and substitute therefor an equalizing bar extending underneath the frame to opposite trucks.

The object ot the present invention is to provide a yielding suspension for track laying vehicles, designed to give a minimum amount of unsprun g weight and which in addition to increasing stability will also increase flexibility. It is apparent that if all of the rollers of each truck unit are to follow the trail at all times it is necessary that the opposite and adjacent sets of rollers must be capable of independent vertical movement, previously suggested, but more important, 1t is essential that the rollers of each individual unit be also capable of independent vertical movement or angular movement about a common center. This additional movement within as supporting unit insures maximum tractive contact with the ground at all times, eliminates unequal strains on the yielding connection to the frame, preserves the equilibrium of the tractor and distributes the weight through all of its supporting rollers equally.

The units of the supporting members being independently mounted receive and absorb their own individual stresses without receiving the strains or stresses from the adjoining units due to obstructions thereunder or to unusual weaving of the frame or other displacements.

It is evident that were the main frame to be mounted directly on the yielding connections the Weaving and swaying of the frame would rapidly deform the connections and render the suspension inoperative. Consequently, the present invention further aims to provide a practical suspension in which a. novel frame insures proper alignment of the rollers with the track and is prevented from distorting its yielding connections with the roller units by vertical pilot columns which project through the frame and which also Carry idlers for supporting the upper run of the track.

Inasmuch as it is contemplated to use rubber-tired rollers which may require more frequent renewal the units may be separately removed from the frame and new units quickly substituted.

To these and other ends, my invention consists in the construction, arrangement, and combination of elements, described hereinafter and pointed out in the claims forming a part of this specification.

A practical embodiment of my invention is illustrated in the accompanying drawings, in which,

Fig. 1 is a View in side elevation of a tractor constructed in accordance with the invention;

Fig. 2 is an enlarged transverse sectional view taken through a supporting unit;

Fig. 3 is a view in side elevation of a unit;

Fig. 4 is a. sectional view taken on the line 4-1l of Fig. 3;

Fig. 5 is a sectional view taken on the line 5-5 ot Fig. 3;

Fig. 6 is a detail sectional view of a link pivot;

Fig. 7 is a detail view partly in section of the spring supporting seat;

Fig. 8 is a view in side elevation showing the application of the supporting units to a conventional tractor frame;

Fig. 9 is a fragmentary plan view partly in section of a modified form of unit shown in Fig. 8; and

Fig. 10 is a detailed sectional view of the upper end of the spring casing.

Referring to the drawings by characters and numerals of reference:

The vehicle consists of the usual main frame A carrying power a power plant B and having a suitable transmission to the drive sprocket C for driving a pair of endless tracks D about front idlers E.

Secured to each side of the main frame A and parallel therewith is a suspension or bogie frame consisting of spaced angular plates 10-10 conveniently reinforced by transverse plates 11 and having vertical casings 12 formed on or secured to the upper or outer frame at regular intervals.

The suspension frame is supported through yielding connections by a plurality of sets of rollers 13 arranged in series on each track, each set consisting of a pair of successive rollers mounted for either angular movement about their common axis or vertical movement and constituting an independent unit following the endless track for supporting the vehicle. As the units are essentially identical, only one will be described.

The rollers 13 are mounted on axles journaled in the opposite ends ot a pair of bent arms 14. The arms are at their bent portion apertured and correspondingly flanged for rotatable mounting on a spindle 15.

0n the outer ends of the spindle 15 are mounted links 16 which are supported on pivot pins 17 passing through parallel ears 11 on the transverse plates 11 for the purpose of bracing each unit against lateral and longitudinal displacement. The pivot pins are held against removal by split pins 18 and may be provided with a lubricator 19 (see Fig. 6) for an obvious purpose.

The spindle bearing of each link is slotted to slide over a key 2O disposed in a slot in the spindle, suiiicient clearance being maintained to permit relative rotational movement as the spindle is raised vertically and the links swung about their pivots. The links are of a length to describe a relative large arc so that considerable vertical movement of the spindle may be obtained without unduly oscillating the spindle and its attendant structure. The assembly is held to the spindle and axles by means of nuts 21 threaded thereon and locked in place by means of a screw 22, the head of which may be selectively disposed in a slot in the nut and held against removal by a cotter pin 23.

Embracing the central portion of the spindle is a sleeve 24 formed within an elongated pilot column 25 at right angles to the axis rounded by leather rings 26 to prevent dust e andv otherl foreign matter 'from entering the spindle. The lowermost portion of the pilot column 25 is threaded for the reception of an adjusting nut 27 and an annular seat 28, the seat being only threaded through a portion of its length to provide greater range of adjustment. Surrounding the column and coni'ined between the seat 28 and the shaped head 29 ot the vertical casing 12 are yielding elements, speciiically an inner helical spring 3() and an outer spring 31, it being readily apparent that any desired number of springs may be used.

Threaded into the aperture of the casing is a cylindrical metal bearing 32, whose inner surface is rounded to establish a free pivot for the column as it is oscillated by the links 16 when an obstruction is encountered by the unit, resulting in an upward movement of the unit while the frame maintains an even keel. For this reason also the spring seat on the casing head is spaced from the sides of the column.

Threaded to the upper portion of the column is a sleeve 33 having a castellated head for receiving a locking pin 34, which may be selectively inserted through the column. Embracing the sleeve underneath its head is a bumper of any suitable type, specilically a resilient washer 35 conlined between annular plates 36, whereby to yieldingly limit the downward movement of the column. It will be apparent that the springs 30 and 31 will cushion the upward movement of the column when a stop 37 on the column comes in contact with the lowermost portion of the spring seat in the casing head.

It has been found that it is only necessary to furnish bumpers for the end column although they may be provided on the intermediatel columns, if desired. Similarly, there may be mounted on only the end casing 12, brackets 38 carrying rollers 39 for supporting the upper run of the track.

Vhen encountering an obstruction, the front roller of each unit is free to be moved angularly upward to follow the obstruction, this movement swinging the bent arms about the spindle and causing either downwarrgl pressure or downward movement of the rear roller according to the nature of the obstruction. Vhen the iront roller passes over the crest ot the obstruction the arms are iree to swing in the opposite direction thereby reversing the direction ot movement of the rollers and enabling each roller, at all times, to follow the track. Vilhcn astride the obstruction both the rollers and their common axis are free to be moved upward to compress the spring and avoid disturbing the equilibrium of the vehicle.

lill) 4 the main frame.

The outer bogie trame 10 may be provided with apertures 40 or with doors to permit the insertion of a wrench tor manipulating the nuts after assembly to adjust the suspension springs and regulate the keel of the vehicle for either operating under a maximum draw bar pull or with no trailed load.

In the modified form shown in Figures 8, 9, and l0, the rollers ot a unit aremounted between the ends of two triangular plates 4l, the apical portion of each plate being rotatably mounted on the end ot a spindle 42. Centrally mounted on the spindle, is a sleeve 43 formed with a column 44 and having a seat 45 for a spring 46. The column projects through a casing 47 Working in a metal bearing 48 which is loosely confined between an annular ledge 49 on the casing and a retaining ring 50.

The casing may be conveniently mounted on a popular type ol suspension frame by spanning the parallel beams ot the frame, thereby enabling the suspension units herein disclosed to replace the conventional trucks now in use.

The curved links 5l instead of being keyed to the spindle may be revolvably mounted on a hub cap 52 and the links of adjacent unitsmay be supported from a common pivot 53.

l/Llhile in the foregoing there has been illustrated and described such combination and arrangement ot elements as constitute the preferred embodiment ot my invention, it is nevertheless desired to emphasize the :tact that interpretation of the invention should only be conclusive when made in the light ot the subjoined claims.

I claim:

l. A suspension tor track laying vehicles, embodying a. frame consisting of spaced an- `gular plates, a vertically disposed casing on the upper plate, a supporting unit between the plates including a spindle, arms centrally pivoted on the spindle, rollers mounted at the extremities of the arms, a pilot column mounted on the spindle and projecting through the casing, springs surrounding the column and abutting the casing head, means for adjustably supporting the other ends of the springs, means for limiting vertical movement of the unit in either direction, and means tor preventing lateral and longitudinal displacement ol' the unit.

2. A suspension for track-laying vehicles embodying a frame, an up-standing casing on said frame, a supporting unit for the frame including a spindle, a pair of successive rollers mounted for angular movement about the spindle as a common center, a pilot column mounted on the spindleand extending through the casing, yielding means interposed between the column and casing, means for limiting the vertical movement of the unit in either direction and means for preventing displacement ot the unit.

3. A suspension for track-laying vehicles embodying a trame, a supporting unit for the Ytrame including a spindle, a pair of successively mounted rollers movable angularly about the spindle, a pilot column mounted on the spindle, a yielding connection between the unit and frame, and a pair of links pivoted to the trame and loosely connected to the spindle, said links being of relatively great length to permit maximum vertical movement of the unit without undue oscillation.

4. A suspension for track-laying vehicles embodying a trame, a supporting unit for the trame including a spindle, a pair of successively mounted rollers movable angularly about the spindle, a pilot column mounted on the spindle, a yielding connection between the unit and trame, and a pair of links pivoted to the trame and loosely connected to the spindle.

5. A suspension tor track laying vehicles embodying a trame; a supporting unit including a pilot column, a rockable track engaging element, and a pivotal connection between the pilot column and element to permit rocking movement of the latter; a yielding connection between the unit and frame, and means tor bracing the unit against lateral and longitudinal displacement.

6. A suspension for track laying vehicles embodying' a trame; a supporting unit including a pilot column, a track engaging element, and a connection between the pilot column and element to permit rocking movement of the latter; a yielding connection between the unit and trame and means for bracing the unit against lateral and longitudinal displacement, said means comprising a link con` nection between the unit and trame.

7. A suspension for track laying vehicles embodying a tra-Ine; a plurality ot independent supporting units for the frame, each unit including a pilot column, a roller carrying element pivoted to the column for rocking movement, a plurality ot successive rollers carried by the element; a yielding connection between each unit and trame, and means for racing each unit against lateral and longi tudinal displacement.

8. A suspension for track laying` vehicles embodying a trame; a plurality ot independent supporting units for the trame, each unit including a pilot column, a roller carrying ele ment pivoted to the column i'or rocking movement, a plurality of successive rollers carried by the element; a yleldinglr connection between each unit and the frame, and means for bracing each unit againstlateral and 5 longitudinal displacement, said means comprisng a link connection between the unit and frame.

HARRY A. KNOX. 

